SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e648281a14209ec80bfd26142482ede1b74e99727df092272d41d9023c595b9f' 
  AND token = 'Sch4nQbRhigkcwb9eowwZKCKYUoNAPN9nWtcNNmLVuY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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