SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '513ab72d52de9156973af8039ae8628cdfc57b2e1348cf214724a29730d419ee' 
  AND token = 'mb2BvQNadiYw+9vrcjSEURkp8I12Hsp0l4WMkYIQsI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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