SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e325ecefb2ee09d0b6a45e55ba1e4bcc7eefeeb1e75ce7ffc920871877ae94c4' 
  AND token = 'bFsLaFg6bAjEPwFycdDeZAsGnopUgg8H3/tLfjaa8hk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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