SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6150fdb07b6934124245141fe3e80460219bf631ddc6e99ac971259aa78d2031' 
  AND token = 'iQ+N3DvPdHiLyq0ZdZYa3M1oueYkXFkazpTUjBi6YNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}