SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '172ce3f3ed56576dab71c1c66d2a8282144e232a24b2a140643ce4cfc5546d9a' 
  AND token = 'i+FGZKzlpzfiR9KRPQm+Y2zZiVkOEWOhDV+NuDXqz/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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