SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '56faaf52fb5e7617a21b71dff4bbbfaec136667e33d15db06d9e3d00c192c068' 
  AND token = '3HFcg6VwM5qDKanzs/LXagYydlFEy0f2GGYVJP0IODQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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