Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c839fda99713c283b270d69c92be8aae8b9ef15ca7212d26a2971a944961e0a3' 
  AND token = 'f6Q2RThfaUfVGMatMVHE2xRlefOnvOME272rV6zbY/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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