SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '741515b0919d557767b131aa6ca20722ea252bfad42ecfc410dbd94cbf6702d0' 
  AND token = 'A4hPeOjqA8035+2AswYgn7FXJihVF8OVhLb2blKBAoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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