SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e7482c0d8f93e2b69901876e293517fd9445906c6fee864f5953ba3b077591c' 
  AND token = 'VIAMHFWM5edeaBAh3UHhbhLWXB0CtKsoGRqe4RJjmsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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