SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c95b2cf1e872c4d511166fd4f4b37aea623456f7c2bff41b909a4f7bc68b5734' 
  AND token = 'pwpTqssg4dYMB0aMolDEiq8Ilz8ZKvYf0Lg38hszZng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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