SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6035e94a0786aa558e3af63b1022cff801a712fb8780f953fd3e733e257a7628' 
  AND token = 'NXEQqBQlWAZJtchxocOLAhTZQLeJrmGIeVruxgs+weQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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