SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b844bf53a43521d4fd594e984370baf98e0d16e12e0ba7d026f0daf18a235868' 
  AND token = '5VPrHRWVlmflMJuMp8qnG0X3uQcWJRzwn9vgA8hYpPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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