SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f49dcaeeecff288e0853278e9605072e2c3111609fc4aa6af3709f7935006b55' 
  AND token = 'XhikxCEMFxe1ajiSumGiUodEozBKPLcycsNfxqp8iyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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