SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46d03cc77cdbab312e9e11fe111b0a584bb1bf6af295f63953970ffd10371ef3' 
  AND token = 'ZQNN3cKvOjlbhPUHwXiCizJPQw7hfUWMEL8O9k6lDLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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