SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'acd986b96abc99c313c57c5d16b07c7c6c88afef894ce521b6c54274fefb79a9' 
  AND token = '88XGL5ISKdUmcvGwiXANM4OXBWT3wjbnZhN2SVUR1ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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