SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8331830c497fb0c18013a5d25bf1a784d18dde8df30e8c65f2b4810fcfeffd5e' 
  AND token = 'Em0CSDUHgDLIEt0hWQWAqJ2wPdy1QDK6NBIw7pQatyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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