Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3d7dce1c6bdc320d928731bf213c8afeab45c9471995a8162c7efbd47cfb39d' 
  AND token = '863dL0bA57Wprv4mo3pIzc0P25tQnITkPtXPYfsYslE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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