SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4681ee2d7dde81178531fa46f2e0951c275de6c237c7ccdeb61565fff96e1ec6' 
  AND token = 'g7D3q7e/zaQ/C6PbrheRK8wbh8DDTs+M4TKOAGdvAgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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