SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5600420b2f885614acbaf93bc5829b7813a76c36a7ab772729e37b872c6b368' 
  AND token = 'hoIH4HzNGvwzCitlRoYMNtpi9R+dIkFd9Kvry6eFPJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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