SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '22cd77ad1ca6dd202986ac470ed27f305fe8b82e297eb16ebd71fefc9dbf59d5' 
  AND token = 'gBktqZP6F8/lkM/IGnwN7uMfk/qTY1glGq4eK0vwn6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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