SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69c516c4d7354962c9c794d931a07300714057baabbaadf64b92443e9aaee7e0' 
  AND token = 'wVBtTUR8Fq7rGoj/V7pPLauIC8WPGLbB+7ZrBKWm2Ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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