SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f3baf9f4a13bfdfaaec280f9b899f6e14def8cd98f8d089eb9c5a8281306bc3' 
  AND token = 'PkvCgldPiqm7sQCzlXIwChfZKmB8HbrfWX+tjt4MBQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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