SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7e7dac0663aec2dcb0ea95db634bfb314e30df9ec52b6e98a15df1151741900' 
  AND token = 'e2fQzM+5pC3V6nz6anj/iLcih97X8HhM0cYKh8G7Yt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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