SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03efc05e89bc91df7a10fe15691b8023fa80a47c9e2ebc4f5ffea25d3dce7b6a' 
  AND token = '2HXBl+040mKDOLCe5DIpqYWSeOjv6CO+hpLILUDCmJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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