SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b10cd3f79a55ba1ff668d98b9e810c31bf343c6df14767f2aceb7e47892fb22' 
  AND token = 'KlXmX/JjSwEXknkOV97fINerR0sVxKlzuUg/fIuiMoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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