SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '26ef57cddf57711581bde6fe008379bfaedbf7a3d09bb95c405c69547eea4666' 
  AND token = 'o8Zc+edfhMBHV29tSTHiptoXesoMDmJfrAQqasglchc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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