SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe7eccb6b1084ee30aa5aa2bd9cadb7d2496e9be0d027758a44a0d0bafcc2cdd' 
  AND token = 'mdsHM+J37P3V0Qc5DxjkqbTrZG3XgZjeZiynjDADmEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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