SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38fa1b99d9e3516088cbfe6c41181aee2864d032ad9e7ffc5955611d60c580d7' 
  AND token = 'bj5ulQGLq8d+jrflMAzIUgfXHJ6h7UbnY5RblYz/z9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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