SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de8b2db4bdcb2b192f592fb3dc8076136aa271bb8581bb33d6f796d8cc7567f4' 
  AND token = 'sgbp9uoRmPZBuFLFP4+2CRVnaITdjHJpv5+qFQssjZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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