SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb09d7e10a9624c80ba49d133e70281330e37745043ea5f286d07132b5cb456' 
  AND token = 'F/7emBQUHJaxS7OvJdaa+Ti56U2ye5ByFWDksIlj3Hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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