SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f68d25e5e44096f74d468c1db37b55898373cf41df2823c91d4a5922c87be809' 
  AND token = 'ropjZGRKnlUa62BcFKrRjj/9BkThqlpGq0v2K7MkheM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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