SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc7572fe2e1df91b4fa1aa7f8c0eff55db63cc1a21cc489c8fb54a6ca27a6dc' 
  AND token = 'q+XLwNiqeyiQjgBifVPxePsJkIGAhkNR80WremNDFhQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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