SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '448ea9b6592447690d1092cf99a915de078ad69e47bdaa7fe2d27f3712e90cda' 
  AND token = 'mdAith7fI8fDUJJkWeipqByokP7ZhakJ/UW8YNTEG0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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