SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9f5dd538edd1f89acf5f47862895771f2b79cde58d0c50b7441938a674dfa00' 
  AND token = 'EFMNBQP4XGMHhCwDeC/Ap/2auFgzAK9WdCRnq2dcn5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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