SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b09a30e90b4b42f55b08a025b642c16617dcdb56b9bbf1647b51189b47b3835' 
  AND token = 'wSxBOSJHdFViw1mladbdECZNAYzwIhNAfDIe73XL6S8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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