SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a13e7ed8cbcd4d629a71e4015774e87f4e874403977cca5bf7b29d65eabeb620' 
  AND token = 'AZHZivXCdw2X6teoFGG0rB9CU8Dhofsm86MZuhorr1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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