SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e3a60651bc9c57667079390ab8da8f70671465852aaa06795dd845b872b18f5' 
  AND token = 'i55Zv8sGl3CYLSMWMHDlfRvulHbnOGRmJfG3PuEb+6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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