SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67beb0b09092dc604baeee3f916ef3ad559e1bbcacf4e19da9c0aad527c7714c' 
  AND token = '9lm9jv7ajJ25BnZnGRHPCYunnYSiMkoyT577xlfD6Ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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