SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6cbe59f69d4dc8c88b6b75e510157de527fab29fb69be112197696774ce9948c' 
  AND token = 'MpuvzwdeaVBwZcxzh/R4wh+VqDOzJSN/pyLfs54rpuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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