SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28a2928b99c585f57e26adb124ddc5c0a4fd02f8667383c81d21e944f336d673' 
  AND token = 'K2wvMCntVspzyruCGxCKmJboUzKOD+U4PQ09T8llDdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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