SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ec16306302d03d551f496d6ee340f7dd972ce7813092a4ef0f8d86fe33bebbe' 
  AND token = 'LwrE0uPd4CvaJMPDTaQBIYthiOFj/GP4HGQopn0EmkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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