SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bff161ccdee2643d6676504975e70d781091765acdf4a34d860461d356173bfd' 
  AND token = '5LfujvOezDcJIh6bnu5J/AVMsOzoG5sBHbOyt0bzddM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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