SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1882c5a7e816ba97513205ae0e2a33aaa5c546604adb43fed4d5b3d7fb1e6796' 
  AND token = 'uYFo0GIj+967n0sTGLqkzlBWv7MKRgLaoV9ZsIeWUJc=' 
  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"
    }
  }
}