SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddb9d267d293b9833edb6b75b886632ee9b31af175b8237086b528d249216ccd' 
  AND token = 'zYw6x24ZUAIYxfm316hWyPzOkM2CiHRTXYwjQBLp0bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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