SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93c5e6b65f3f07050b9e176827297cf0ce3015a3bd88e32a3b8ea48b5b135d46' 
  AND token = 'ziODF4XeoAh+61PBbQHrUHOJjZPj2rWOmx+4s/cFz4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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