SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3bca7992733435c878bf3ec656d297d6bdc5e3962a9888a612379fcadaa0940c' 
  AND token = 'RVVv8XLvVt14vUmGlef9GU2DoTzRplZXG0HzBkiCQMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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