SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e298fcc41b854285aba2f7babcfd527c2d34bce3b226cbabbd56051fa7818e11' 
  AND token = 'LbsULvp5MDNDTfEP6U62eBktnsBb/6vaFe99n1H5FuA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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