SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2e8bfb141acc532117cfa0df04c209c19aad08165a27dc8723ff0ffce33449c' 
  AND token = 'xWCaxRDwrrsbi6Si/9Zy1iQkb6n93t2w6bStu/Zw1eM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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