SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13fa846865a0d53f2e6672df9a06c35595831fed48f42d516effb94eac47d5ea' 
  AND token = 'BAqYSkS7JZbwVcU/YGwyMAwjrNeAacj7+VVHlLmU6z0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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