SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b439c8defe247dc9b597f1c097ac428cee95c3ec6e5683b9fee9c9828c3ef525' 
  AND token = '3O30oWsd/Fa5pJxsEvpqXYkUgoKDzglHBZ5uFOl/kIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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