SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df271cba424cf055ac23cb369ea0e33634db3a624f9332f7f78281ddffb981fa' 
  AND token = 'CQBUXuLKJqFLLHjaojN/DSGwsWmkKw8EPLLAQ+KDy00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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