SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f341c76a63ee891a8a4bad320311f799ba2e118bbcf613abfc9926c8ff01cd25' 
  AND token = 'HcCwUc0WBIXhGnvuGmAHx/vhcHcW0qVTRnEFPRr7zdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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