SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e888602d6225dfb504557137cc7f1815c9e21d8d6e717bd85257de1f13f0ae7' 
  AND token = 'AzR5E6z7LPYidojXJVbRB9llD2+o/4wxg7GZ2H/yKGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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