SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a20199f9d1067e52845e917c788d3cab65805f14e22007a789f10a127c5e5c27' 
  AND token = 'MT2Qx0LOTU2s3y+A0EMN28NiW7JaaFi3JIOK0rEajXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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