SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f884b36f747a276edb558da27912bde57ab08d7cb70060f560a9223eb972b73' 
  AND token = 'QFowzMB571Ul4zf4ynBvqmMZUWpoMXo104hXFOSUqxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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