SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '662adbe0131d5f5a0a1bb724c166abbabc6dd514ec6724963fdc8fc8c5d4dd31' 
  AND token = 'duhkgR2yme1J1Hp5AWz1fYiDQYWNkdUYBZ9dAfc+IRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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