SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df840e1293d650259b3cd39cd9ceb6ddf0e11cfec79abbb99b5b33f5b3658c4a' 
  AND token = 'fwBmZlkjwkHod1rYoBHdghKTS8OU/JwlaCefxw1S/7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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