SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db0cd440fb1ed75999fb70c4e17eea0466b21dabe41fdbe94e9ff3fa33589e61' 
  AND token = 'XX4xsUxkjOGnsqQvwX8zek+RhUVWlAaavRqM0duTapw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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