SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f3537a263d81fbef51558257b859471b81cfc5cb66b15bc54865f0233f0869b' 
  AND token = 'BhMlMCXb+SiycvB0g/n9DXUZ52+lGPbEmUrTuuETwPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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