SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '534938bd53b9f72b156e60cb3f760fc7c02671656fc698d14dcef0cb3894f179' 
  AND token = '23kXlFoOgDG0/HQgIALZpZqOEHLpRaP2TYxTWFuxPCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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