SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c7d0879e14230aa76db1d519483a93358ab69455c03b5d2f3d872136a19579f' 
  AND token = 'tOStRJFrVgb9iQJoxK+kWYdC0SHqy7HVu/nMU1YsZhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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