SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '15a86589350e797d8a3dad151c8a4ff09eba42e1c8783fec8a1eafe21f28b237' 
  AND token = 'g75m+RXVN7KZQyxjhu6uZCOt/PbTZOGquyjWEHB4z9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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