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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d33bf5c739f061bc79761ba3a4bc9dadd6830cb6f453b998cf938d0664e33bb' 
  AND token = 'jINmFaE6H9eMv3cHliURoVGjYqakuMphON7SfGmQrl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}