SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f736fc4d62b91485c530503fabfe16cc5501314d3c91cf9cd339122591b42e35' 
  AND token = 'rcNp66QwHFJffFFzVRcWHrrrnfIWx+aCtAmGlIMOB+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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