Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b89c7cbe70a836bcf67c995d9eccbaa3b9aea2918914422467df86f9b258a9c2' 
  AND token = 'CobV1bdjQol66E/MU9MhAfK8kkJ9RwlDYF2tdZK7HFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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