SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cdc14dd2252f7c514bf110437fb917e3ffb279e1c5fa7009c9e17eadf3d3556' 
  AND token = 'd49IoqaU3BLk3sBrbiJGFDUsw1Gz0AUQjJea1visgK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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