SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2acc271d97274604d6f6774854b783d03deb51b5a68319a110b7608d9e5989c9' 
  AND token = 'B3KxRfDj2bSt8zeKBvL9cZ+lj1yUDiCjLOuRa7MZwAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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