SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '448fc244772cd7377791b7139a152dc49b6f8b679583b37e7d841543a86d1ced' 
  AND token = 'sasdkRnZkMvp7wyNWvzPWi6aMxfcv4rrbdGFwJLzLGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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