SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0768a4668d8f5b172943da34a5831b92b81ef98dcdbb6cc79cb0fd9d0e6c2188' 
  AND token = '8yXe1GXeK03m0bGuds/kAWbH0wvTaEy3YyZ6W5EdV0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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