SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71faed710775072ea067027a72cebaa9f54cae86ea2809194485ce863b42d24d' 
  AND token = 'cAXLvyDDSd1WMPxkQ2sNxPWEIq28kBBCe4UAaa6Z1ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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