SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '83b81b31a1b8f5ce060df3d6a5d999ba0e96e83a40bf1584a558e6bf618aeb12' 
  AND token = 'BvU1x2hecPbx7EH34GAVgdSlqXMQleEUwPDaK+VRHRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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