SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d09345aa0b18c35aa9337dff0ee3b4788d79288cd0694bb700d1f64cfe5c0fd' 
  AND token = 'ar9CV+TxulmqpO6m2+ewhoOgfKyW7vPYXw1864pvbJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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