SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c4665742dc6632b18a6b096e2f9de599e2230a5f81fd347d17d0e17650211917' 
  AND token = '0tw/JC7U8bGrfxfBQNluW+CZGPgR5p3sJWBpnR43xuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}