SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e71f8cdb7cf01d5744fa05b6da0d374ee4220c24265a72ef1795d5fb1ee64c9' 
  AND token = 'YdwWV+10iC7K+doLo1y7vNRHLZzlJTPPi6R/Dx9q0Ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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