SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cda83051f08f93ac7ea021518c0dd334e4f0a3b61e8891147ae98110164de6a1' 
  AND token = '37cOoxrVqZRDE1XZ13iG/6HWMeEuih9HDrFROZXAmxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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