SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e11d3bf427752427e7575962450c69727efeb1bde56eeda5cfdd8b68afb63a1f' 
  AND token = '2jbjsNWW11Ijrq8sVM1Hq84sotvwYkYN7ibr3gudkSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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