SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de70f5e3ce272bd4ad3c34d19d3c0ee90aaba148bf437f73c65a22d5306431fc' 
  AND token = 'kqc7XRI6+0YPI80IFNPA0qF8RAx8DtkKyjuvnp7SNhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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