SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3529ad82c8ac829357f740fc23c06b4094e1705ca52ed6e72f711af60617339f' 
  AND token = 'ZfG03QGxImPEhlSWcziInwSSbVmQVkaQy7a6lrvRxEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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