SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6d523530ca171c2c2c86bde051ad65d35020a0f3608322b05e53673f6d6ec43' 
  AND token = 'bCvwQsdo8S+bFNHfygCyBcrL0rmWQIy1ktjafgy3qrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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