SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f74f0c111ed25d15adbd9d26d6c2246819051798f95fd5d33c1291ba7095f19' 
  AND token = '7os/bU9/hWIpF9gYgMQep/OR8T4e+2+Bdk/5W1/KsTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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