SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed3349fb11956fe798768a0602c74bb4522a90e9d7943205c630fe5780012b48' 
  AND token = 'SmNSVXbtg1ZeLQ9GbkR6yvCZfYzvkTw89jgjNMRYwuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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