SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b43eb58c23c8024c4dd9e169adb521c0d40f07ffe2d7f8d6fd826e6c6090d288' 
  AND token = 'CYXgwl+WOfOHm5O4qntb8J6C/bQMRuVZYj3rIuBF6fQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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