SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cecbb0335f48ee1f7eb90746f00d1c5bd3ba1c288f312c90cebf761cad95120' 
  AND token = 'nt4qNgjt2OC9SwrZqRx0GULBbOTfbNfhxpr5en59N8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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