SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f30a6a4f01615aa15d73ce89e8a48a6c8dc1f3ad99d839edd8570e8e4e42721' 
  AND token = '6y0bvOMk3oVBbMym+NuF0Fu+jrL977R8JwqZNo1vTw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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