SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '361c256a6127146f8ee3445547804f5821598d494ba68176847b52d3623c8a20' 
  AND token = 'xaKHBNQF/e7aIh83FUW4LlncaBtIOOpetVYbwwaIbAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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