SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f79bc3214cc2f2c14de3af78e30153b09b386ff5be599001a0d664ae30bda194' 
  AND token = 'WfkQIJWdY8FEN/CtbYD7ED9/01fDK5ExFaNBEc43D/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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