SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '477aa1bdfc189e76987a108843bd3a89a29df01acaf1575dceeaddb3ba4d6720' 
  AND token = '1kyFKU6D53+xJHDKfEQWeqtuWVbgkiJpmk6D6Pl+MvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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