SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4375d988082ca3fe1301fd055df54ca1f4d7ecbc8e430d64889f135353833bf' 
  AND token = 'bJgaPGjN4l2qcIb3ShSpXFU1KeMqK/EXqeU9uQjIMlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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