SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73113aba9f1064ba8f5a67b0e5dba96ba05d145c079bb8bc4cc15b7ab9468aa4' 
  AND token = 'JMPIh+Qy+l1gpsz1pB0fWFQNjw3GNAcW4a1yWDGG9UQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}