SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ee0e94d881e9dd9f9c889659f38e58fe30fb73b7121f18f72159a89ec20e6b3' 
  AND token = 'f3E+FkRPyq2mFqYCHnAecWBZuE9F7pWvSz0fWbjfaxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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