SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf43adf71817b9e3b659a410e4dede773f87d351e9aa955a555611e60608dc19' 
  AND token = '5Yc9SyWyfbLgffPxDknkXEoo+ch5xlzKplo8vN3Y+Uk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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