SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b052ac38e5b00540911199b3d791ab08b6e6b214536dd4c8824ab76c1e80e89' 
  AND token = 'aRCbo9UnkAScOaOf//AsUaul9XHlvVidaJRqhqby+wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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