SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd966f787d4fe1782516517ac010b50e73f45460c35d467af6153c16922fcee1' 
  AND token = 'I/1yYinF7Uy9ZJ8PJljPZlvbcQ4dwboXtVTQIcEzA/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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