SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f54efb971a39853d995d32444b585f7faae6564d23c02bd5ecbf61dcc0565485' 
  AND token = 'hK3x/mUO2xebYpMGEE+SylWq8TTJ9FarRzk3ZTOgtB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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