SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10df821a23bee08bc78dfcfb63419877aa56a2d6825b340737d98e98d8d79914' 
  AND token = 'xFpPyOc9ejmHGquf/ULgm4S91BZv5Z05hhXizspYdjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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