SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '605f5f1fa25a3430a483868403a95841dcc218d9d805822c851d15e91e21641b' 
  AND token = 'mu0fFqeIccD6fKENnvd4i5zu133jUUyi9XccTJFukc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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