SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1530a6727cd806f60531174efc775779f8d54dc46148ef6b4a3d5ada9f829701' 
  AND token = 'GglxNiMBI0eIajZu4Q6MDp3FYc7YmR0WnoJLfD8xOSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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