SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43dafbc3caf824b92fcf5441538df1ea77f20d478cf37f4baf75d58f79191f66' 
  AND token = 'q7cZzTfa4sZmbHgAmUvoDHZvYDPj7YR2lxTdVgUekqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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