SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c17bdae2e991eb39052deecc2358002c7926b1d34e1528d56c158cf8595c7a3c' 
  AND token = '3Ukl1449Y2uJVl96hVcYCLwsXLSbTkGonuUna4AH70A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}