SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '58e81598650b3fc82b59a7b3c03efe8fe959c6a3cba6d30aa10f34a73728fa7f' 
  AND token = 'YBMt1+DnBnTtgc+Oh/kVqiYCBsh0p79swfqWmDt/Mbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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