SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e7186c448016d70c3dd7a69a7e19cf5969ba5de11dab4d245d6600af0307b0' 
  AND token = 'xYCBDDuoK+5Z+suw0lDCyEj9O801wDKu45WHbxyAePI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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